Electronic devices include semiconductor integrated circuits (LSI) with a logic circuit or a sequential circuit, which are composed of CMOS (Complementary Metal Oxide Semiconductor), or the like, and a power supply system with different power supply voltages. The electronic devices are provided with a level shifter for shifting signal levels between different power supplies. The level shifter has two types. One of the two types is simplex, and the other of the two types is duplex.
Recently, a plurality of level shift switches is used for consumer and industrial electronic devices, which have high functionality, high speed, and multiple power supplies. Duplex level shifters are required to have fast operation without a directional switching signal (DIR control signal). The duplex level shifters include level-shift switches based on semiconductor switch circuitry. The level-shift switches are strongly required to have high speed.